To achieve the goals of the Pancreatic Cancer Detection Consortium (PCDC), we will leverage Mayo Clinic research registries, biorepositories, and our pancreatic neoplasia practice to develop a resource for collaborative research aimed at improved detection of early stage pancreatic ductal adenocarcinoma (PDAC) and its precursors. Mayo Clinic is an established center of excellence for research in pancreatic conditions, and its ongoing biospecimen resources contain blood samples from ultra- rapidly identified and prospectively enrolled PDAC patients (n=3,092); high risk members in familial pancreatic kindreds (n=2,575); patients with high risk pancreatic conditions (n=1,599); and healthy controls (n=2,791). We will introduce longitudinal biospecimen collection from subjects to validate biomarker performance in various settings. Innovatively identified biomarkers will be evaluated: using cell reprogramming of late stage human PDAC generated cells, the Zaret lab found that, when re-differentiated, underwent early stages of PDAC leading to new candidate biomarkers, including THBS2; the Ahlquist lab identified novel methylated DNA markers for PDAC and high grade dysplasia using unbiased whole methylome sequencing. Our Specific Aims are to: (1) Construct formal biospecimen sets from DNA, serum, or plasma suitable for PRoBE Phase 2 and 3 biomarker validation studies. We will use existing resources and also prospectively collect blood and pancreatic juice every 1-2 years from patients with pancreatic cysts; we will collect blood every 2 years from existing and prospectively recruited high risk family members >age 50. (2) Validate serum or plasma biomarkers for early detection of pancreatic cancer as directed by the evidence and PCDC consensus in Phase 2 and 3 studies. We will perform a Phase 3 validation of THBS2 and CA19-9 suitable for the primary care setting using PLCO samples. We will perform a Phase 2 validation of THBS2 and CA19-9 suitable for a pancreatology clinic setting of high risk subjects to discriminate PDAC from chronic pancreatitis, cystic neoplasms, or neuroendocrine tumors. We will perform a Phase 2 validation of a panel of methylated DNA markers (including ADCY1, CD1D, BMP3, CLEC11A, TWIST1, ELMO) to discriminate healthy subjects from PDAC patients. (3) Perform a Phase 2 study to validate biomarkers for early detection of pancreatic cancer or high grade dysplasia in patients with pancreatic cysts. We will examine the DNA methylation markers (including ZNF781, PRKCB, CD1D, BMP3, CLEC11A, HOXA, ELMO) that discriminate low grade dysplasia from high grade dysplasia in IPMN. We will validate a panel of these biomarkers in prospectively collected plasma and pancreatic juice of pancreatic cyst patients. Our resources and experience are extensive, from a depth of biobanking experience and biospecimens to epidemiology, gastroenterology, novel biomarker development, and biostatistics expertise relevant to early detection and biomarker validation in PDAC.